/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smackx;

import org.jivesoftware.smack.packet.PacketExtension;
import org.jivesoftware.smack.provider.PacketExtensionProvider;
import org.xmlpull.v1.XmlPullParser;

/**
 * A group chat invitation packet extension, which is used to invite other users
 * to a group chat room. To invite a user to a group chat room, address a new
 * message to the user and set the room name appropriately, as in the following
 * code example:
 * 
 * <pre>
 * Message message = new Message("user@chat.example.com");
 * message.setBody("Join me for a group chat!");
 * message.addExtension(new GroupChatInvitation("room@chat.example.com"););
 * con.sendPacket(message);
 * </pre>
 * 
 * To listen for group chat invitations, use a PacketExtensionFilter for the
 * <tt>x</tt> element name and <tt>jabber:x:conference</tt> namespace, as in the
 * following code example:
 * 
 * <pre>
 * PacketFilter filter = new PacketExtensionFilter(&quot;x&quot;, &quot;jabber:x:conference&quot;);
 * // Create a packet collector or packet listeners using the filter...
 * </pre>
 * 
 * <b>Note</b>: this protocol is outdated now that the Multi-User Chat (MUC) JEP
 * is available (<a href="http://www.jabber.org/jeps/jep-0045.html">JEP-45</a>).
 * However, most existing clients still use this older protocol. Once MUC
 * support becomes more widespread, this API may be deprecated.
 * 
 * @author Matt Tucker
 */
public class GroupChatInvitation implements PacketExtension {

	/**
	 * Element name of the packet extension.
	 */
	public static final String ELEMENT_NAME = "x";

	/**
	 * Namespace of the packet extension.
	 */
	public static final String NAMESPACE = "jabber:x:conference";

	private String roomAddress;

	/**
	 * Creates a new group chat invitation to the specified room address.
	 * GroupChat room addresses are in the form <tt>room@service</tt>, where
	 * <tt>service</tt> is the name of groupchat server, such as
	 * <tt>chat.example.com</tt>.
	 * 
	 * @param roomAddress
	 *            the address of the group chat room.
	 */
	public GroupChatInvitation(String roomAddress) {
		this.roomAddress = roomAddress;
	}

	/**
	 * Returns the address of the group chat room. GroupChat room addresses are
	 * in the form <tt>room@service</tt>, where <tt>service</tt> is the name of
	 * groupchat server, such as <tt>chat.example.com</tt>.
	 * 
	 * @return the address of the group chat room.
	 */
	public String getRoomAddress() {
		return roomAddress;
	}

	public String getElementName() {
		return ELEMENT_NAME;
	}

	public String getNamespace() {
		return NAMESPACE;
	}

	public String toXML() {
		StringBuilder buf = new StringBuilder();
		buf.append("<x xmlns=\"jabber:x:conference\" jid=\"")
				.append(roomAddress).append("\"/>");
		return buf.toString();
	}

	public static class Provider implements PacketExtensionProvider {
		public PacketExtension parseExtension(XmlPullParser parser)
				throws Exception {
			String roomAddress = parser.getAttributeValue("", "jid");
			// Advance to end of extension.
			parser.next();
			return new GroupChatInvitation(roomAddress);
		}
	}
}